Copper oxide nanomaterial saturable absorber as a new passive Q-switcher in erbium-doped fiber laser ring cavity configuration

A passively Q-switched erbium-doped fiber laser (EDFL) operating at 1560 nm is demonstrated by using a copper oxide (CuO) film as a saturable absorber (SA). The SA was prepared by embedding CuO nanoparticles (NPs) into a polyvinyl alcohol (PVA) by solution casting method. The CuO-SA has a modulation depth of 3.5% and a saturation intensity of 3.3 MW/cm2. By incorporating the CuO-SA into the laser cavity, stable Q-switched pulses were achieved at pump threshold of 70 mW. A maximum pulse energy of 66 nJ, tunable pulse repetition rate (P.R.R.) from 69 to 83 kHz, with a shortest pulse width of 2.6 µs were recorded at pump power of 159 mW. To the best of author's knowledge, this is the first demonstration of passively Q-switched EDFL based on CuO-SA.